1. Field of the Invention
The present invention relates to an information recording and reproducing apparatus for an optical information recording and reproducing apparatus for an optical information recording medium wherein information is recorded by forming a pit upon application of a light beam to the recording medium while aligning an optical head to a track position, and information is read from a pit by using the light beam.
2. Description of the Related Art
For an optical head, means is provided for generating a tracking error signal whose polarity changes between a positive polarity and negative polarity in response to a track traverse by the optical head. A track traverse detecting signal is generated by comparing the tracking error signal with a reference signal.
A conventional information recording and reproducing apparatus uses a fixed reference signal so that a tracking error signal of a low level is not detected in some case. Furthermore, when noises having substantially a large level are generated in the circuit, these noises may be detected as a track traverse, thereby forming an incorrect track traverse detecting signal. Further, if the optical system is adjusted improperly, a shoulder is generated on a tracking error signal, thereby forming an incorrect track traverse detecting signal. Still further, an incorrect track traverse detecting signal may be generated by a distortion of the tracking error signal caused by dusts or scratches on the surface of an optical image recording medium.